/*
* Copyright 2001-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.ajax4jsf.util.base64;
import org.ajax4jsf.Messages;
/**
* Provides Base64 encoding and decoding like defined by RFC 2045, but with little difference : chars '=' '+' and '/' ,
* incorrectly processed in URL by any browsers, replaced by '_' '-' '!',
*
* @author Apache Software Foundation
* @version $Id: URL64Codec.java,v 1.1.2.1 2007/01/09 18:59:11 alexsmirnov Exp $
* @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>
* @since 1.0-dev
*/
public class URL64Codec implements BinaryEncoder, BinaryDecoder {
/**
* The base length.
*/
static final int BASELENGTH = 255;
/**
* Chunk size per RFC 2045 section 6.8.
* <p/>
* <p>
* The {@value} character limit does not count the trailing CRLF, but counts all other characters, including any equal
* signs.
* </p>
*
* @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 6.8</a>
*/
static final int CHUNK_SIZE = 76;
/**
* Chunk separator per RFC 2045 section 2.1.
*
* @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a>
*/
static final byte[] CHUNK_SEPARATOR = "\r\n".getBytes();
/**
* Used to calculate the number of bits in a byte.
*/
static final int EIGHTBIT = 8;
/**
* Used to get the number of Quadruples.
*/
static final int FOURBYTE = 4;
/**
* Lookup length.
*/
static final int LOOKUPLENGTH = 64;
/**
* Byte used to pad output. instesd of '=' in base64, used '_'
*/
static final byte PAD = (byte) '_';
/**
* Used to test the sign of a byte.
*/
static final int SIGN = -128;
/**
* Used when encoding something which has fewer than 24 bits.
*/
static final int SIXTEENBIT = 16;
/**
* Used to determine how many bits data contains.
*/
static final int TWENTYFOURBITGROUP = 24;
// Create arrays to hold the base64 characters and a
// lookup for base64 chars
private static byte[] base64Alphabet = new byte[BASELENGTH];
private static byte[] lookUpBase64Alphabet = new byte[LOOKUPLENGTH];
// Populating the lookup and character arrays
static {
for (int i = 0; i < BASELENGTH; i++) {
base64Alphabet[i] = (byte) -1;
}
for (int i = 'Z'; i >= 'A'; i--) {
base64Alphabet[i] = (byte) (i - 'A');
}
for (int i = 'z'; i >= 'a'; i--) {
base64Alphabet[i] = (byte) (i - 'a' + 26);
}
for (int i = '9'; i >= '0'; i--) {
base64Alphabet[i] = (byte) (i - '0' + 52);
}
// To compatible with URL format, change '+' and '/' to :
base64Alphabet['-'] = 62;
base64Alphabet['!'] = 63;
for (int i = 0; i <= 25; i++) {
lookUpBase64Alphabet[i] = (byte) ('A' + i);
}
int j = 0;
for (int i = 26; i <= 51; i++, j++) {
lookUpBase64Alphabet[i] = (byte) ('a' + j);
}
j = 0;
for (int i = 52; i <= 61; i++, j++) {
lookUpBase64Alphabet[i] = (byte) ('0' + j);
}
// To compatible with URL format, change '+' and '/' to :
lookUpBase64Alphabet[62] = (byte) '-';
lookUpBase64Alphabet[63] = (byte) '!';
}
private static boolean isBase64(byte octect) {
if (octect == PAD) {
return true;
} else {
return base64Alphabet[octect] != -1;
}
}
/**
* Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.
*
* @param arrayOctect byte array to test
* @return true if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; false, otherwise
*/
public static boolean isArrayByteBase64(byte[] arrayOctect) {
arrayOctect = discardWhitespace(arrayOctect);
int length = arrayOctect.length;
if (length == 0) {
// shouldn't a 0 length array be valid base64 data?
// return false;
return true;
}
for (int i = 0; i < length; i++) {
if (!isBase64(arrayOctect[i])) {
return false;
}
}
return true;
}
/**
* Encodes binary data using the base64 algorithm but does not chunk the output.
*
* @param binaryData binary data to encode
* @return Base64 characters
*/
public static byte[] encodeBase64(byte[] binaryData) {
return encodeBase64(binaryData, false);
}
/**
* Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks
*
* @param binaryData binary data to encode
* @return Base64 characters chunked in 76 character blocks
*/
public static byte[] encodeBase64Chunked(byte[] binaryData) {
return encodeBase64(binaryData, true);
}
/**
* Decodes an Object using the base64 algorithm. This method is provided in order to satisfy the requirements of the Decoder
* interface, and will throw a DecoderException if the supplied object is not of type byte[].
*
* @param pObject Object to decode
* @return An object (of type byte[]) containing the binary data which corresponds to the byte[] supplied.
* @throws DecoderException if the parameter supplied is not of type byte[]
*/
public Object decode(Object pObject) throws DecoderException {
if (!(pObject instanceof byte[])) {
throw new DecoderException(Messages.getMessage(Messages.NO_BYTE_ARRAY_ERROR));
}
return decode((byte[]) pObject);
}
/**
* Decodes a byte[] containing containing characters in the Base64 alphabet.
*
* @param pArray A byte array containing Base64 character data
* @return a byte array containing binary data
*/
public byte[] decode(byte[] pArray) {
return decodeBase64(pArray);
}
/**
* Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
*
* @param binaryData Array containing binary data to encode.
* @param isChunked if isChunked is true this encoder will chunk the base64 output into 76 character blocks
* @return Base64-encoded data.
*/
public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) {
int lengthDataBits = binaryData.length * EIGHTBIT;
int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
byte[] encodedData;
int encodedDataLength = 0;
int nbrChunks = 0;
if (fewerThan24bits != 0) {
// data not divisible by 24 bit
encodedDataLength = (numberTriplets + 1) * 4;
} else {
// 16 or 8 bit
encodedDataLength = numberTriplets * 4;
}
// If the output is to be "chunked" into 76 character sections,
// for compliance with RFC 2045 MIME, then it is important to
// allow for extra length to account for the separator(s)
if (isChunked) {
nbrChunks = (CHUNK_SEPARATOR.length == 0) ? 0 : (int) Math.ceil((float) encodedDataLength / CHUNK_SIZE);
encodedDataLength += nbrChunks * CHUNK_SEPARATOR.length;
}
encodedData = new byte[encodedDataLength];
byte k = 0;
byte l = 0;
byte b1 = 0;
byte b2 = 0;
byte b3 = 0;
int encodedIndex = 0;
int dataIndex = 0;
int i = 0;
int nextSeparatorIndex = CHUNK_SIZE;
int chunksSoFar = 0;
// log.debug("number of triplets = " + numberTriplets);
for (i = 0; i < numberTriplets; i++) {
dataIndex = i * 3;
b1 = binaryData[dataIndex];
b2 = binaryData[dataIndex + 1];
b3 = binaryData[dataIndex + 2];
// log.debug("b1= " + b1 +", b2= " + b2 + ", b3= " + b3);
l = (byte) (b2 & 0x0f);
k = (byte) (b1 & 0x03);
byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) (b1 >> 2 ^ 0xc0);
byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) (b2 >> 4 ^ 0xf0);
byte val3 = ((b3 & SIGN) == 0) ? (byte) (b3 >> 6) : (byte) (b3 >> 6 ^ 0xfc);
encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
// log.debug( "val2 = " + val2 );
// log.debug( "k4 = " + (k<<4) );
// log.debug( "vak = " + (val2 | (k<<4)) );
encodedData[encodedIndex + 1] = lookUpBase64Alphabet[val2 | (k << 4)];
encodedData[encodedIndex + 2] = lookUpBase64Alphabet[(l << 2) | val3];
encodedData[encodedIndex + 3] = lookUpBase64Alphabet[b3 & 0x3f];
encodedIndex += 4;
// If we are chunking, let's put a chunk separator down.
if (isChunked) {
// this assumes that CHUNK_SIZE % 4 == 0
if (encodedIndex == nextSeparatorIndex) {
System.arraycopy(CHUNK_SEPARATOR, 0, encodedData, encodedIndex, CHUNK_SEPARATOR.length);
chunksSoFar++;
nextSeparatorIndex = (CHUNK_SIZE * (chunksSoFar + 1)) + (chunksSoFar * CHUNK_SEPARATOR.length);
encodedIndex += CHUNK_SEPARATOR.length;
}
}
}
// form integral number of 6-bit groups
dataIndex = i * 3;
if (fewerThan24bits == EIGHTBIT) {
b1 = binaryData[dataIndex];
k = (byte) (b1 & 0x03);
// log.debug("b1=" + b1);
// log.debug("b1<<2 = " + (b1>>2) );
byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) (b1 >> 2 ^ 0xc0);
encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
encodedData[encodedIndex + 1] = lookUpBase64Alphabet[k << 4];
encodedData[encodedIndex + 2] = PAD;
encodedData[encodedIndex + 3] = PAD;
} else if (fewerThan24bits == SIXTEENBIT) {
b1 = binaryData[dataIndex];
b2 = binaryData[dataIndex + 1];
l = (byte) (b2 & 0x0f);
k = (byte) (b1 & 0x03);
byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) (b1 >> 2 ^ 0xc0);
byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) (b2 >> 4 ^ 0xf0);
encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
encodedData[encodedIndex + 1] = lookUpBase64Alphabet[val2 | (k << 4)];
encodedData[encodedIndex + 2] = lookUpBase64Alphabet[l << 2];
encodedData[encodedIndex + 3] = PAD;
}
if (isChunked) {
// we also add a separator to the end of the final chunk.
if (chunksSoFar < nbrChunks) {
System.arraycopy(CHUNK_SEPARATOR, 0, encodedData, encodedDataLength - CHUNK_SEPARATOR.length,
CHUNK_SEPARATOR.length);
}
}
return encodedData;
}
/**
* Decodes Base64 data into octects
*
* @param base64Data Byte array containing Base64 data
* @return Array containing decoded data.
*/
public static byte[] decodeBase64(byte[] base64Data) {
// RFC 2045 requires that we discard ALL non-Base64 characters
base64Data = discardNonBase64(base64Data);
// handle the edge case, so we don't have to worry about it later
if (base64Data.length == 0) {
return new byte[0];
}
int numberQuadruple = base64Data.length / FOURBYTE;
byte[] decodedData = null;
byte b1 = 0;
byte b2 = 0;
byte b3 = 0;
byte b4 = 0;
byte marker0 = 0;
byte marker1 = 0;
// Throw away anything not in base64Data
int encodedIndex = 0;
int dataIndex = 0;
// this sizes the output array properly - rlw
int lastData = base64Data.length;
// ignore the '=' padding
while (base64Data[lastData - 1] == PAD) {
if (--lastData == 0) {
return new byte[0];
}
}
decodedData = new byte[lastData - numberQuadruple];
for (int i = 0; i < numberQuadruple; i++) {
dataIndex = i * 4;
marker0 = base64Data[dataIndex + 2];
marker1 = base64Data[dataIndex + 3];
b1 = base64Alphabet[base64Data[dataIndex]];
b2 = base64Alphabet[base64Data[dataIndex + 1]];
if ((marker0 != PAD) && (marker1 != PAD)) {
// No PAD e.g 3cQl
b3 = base64Alphabet[marker0];
b4 = base64Alphabet[marker1];
decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
decodedData[encodedIndex + 1] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
decodedData[encodedIndex + 2] = (byte) (b3 << 6 | b4);
} else if (marker0 == PAD) {
// Two PAD e.g. 3c[Pad][Pad]
decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
} else if (marker1 == PAD) {
// One PAD e.g. 3cQ[Pad]
b3 = base64Alphabet[marker0];
decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
decodedData[encodedIndex + 1] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
}
encodedIndex += 3;
}
return decodedData;
}
/**
* Discards any whitespace from a base-64 encoded block.
*
* @param data The base-64 encoded data to discard the whitespace from.
* @return The data, less whitespace (see RFC 2045).
*/
static byte[] discardWhitespace(byte[] data) {
byte[] groomedData = new byte[data.length];
int bytesCopied = 0;
for (int i = 0; i < data.length; i++) {
switch (data[i]) {
case (byte) ' ':
case (byte) '\n':
case (byte) '\r':
case (byte) '\t':
break;
default:
groomedData[bytesCopied++] = data[i];
}
}
byte[] packedData = new byte[bytesCopied];
System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
return packedData;
}
/**
* Discards any characters outside of the base64 alphabet, per the requirements on page 25 of RFC 2045 - "Any characters
* outside of the base64 alphabet are to be ignored in base64 encoded data."
*
* @param data The base-64 encoded data to groom
* @return The data, less non-base64 characters (see RFC 2045).
*/
static byte[] discardNonBase64(byte[] data) {
byte[] groomedData = new byte[data.length];
int bytesCopied = 0;
for (int i = 0; i < data.length; i++) {
if (isBase64(data[i])) {
groomedData[bytesCopied++] = data[i];
}
}
byte[] packedData = new byte[bytesCopied];
System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
return packedData;
}
// Implementation of the Encoder Interface
/**
* Encodes an Object using the base64 algorithm. This method is provided in order to satisfy the requirements of the Encoder
* interface, and will throw an EncoderException if the supplied object is not of type byte[].
*
* @param pObject Object to encode
* @return An object (of type byte[]) containing the base64 encoded data which corresponds to the byte[] supplied.
* @throws EncoderException if the parameter supplied is not of type byte[]
*/
public Object encode(Object pObject) throws EncoderException {
if (!(pObject instanceof byte[])) {
throw new EncoderException(Messages.getMessage(Messages.NO_BYTE_ARRAY_ERROR));
}
return encode((byte[]) pObject);
}
/**
* Encodes a byte[] containing binary data, into a byte[] containing characters in the Base64 alphabet.
*
* @param pArray a byte array containing binary data
* @return A byte array containing only Base64 character data
*/
public byte[] encode(byte[] pArray) {
return encodeBase64(pArray, false);
}
}